1.
Which electron transitions are responsible for the colours of transition metal compounds?
A.
Between d orbitals and s orbitals
B.
Among the attached ligands
C.
From the metal ion to the attached ligands
D.
Between d orbitals
(Total 1 mark)
(Total 2 marks)
2.
Which metal nitrate solution is coloured?
A.
Zn (NO3)2(aq)
B.
Ni (NO3)2(aq)
C.
Mg (NO3)2(aq)
D.
Sc (NO3)3(aq)
(Total 1 mark)
3.
Which process is responsible for the colour of a transition metal complex?
A.
The absorption of light when electrons move between s orbitals and d orbitals
B.
The emission of light when electrons move between s orbitals and d orbitals
C.
The absorption of light when electrons move between different d orbitals
D.
The emission of light when electrons move between different d orbitals
(Total 1 mark)
IB Questionbank Chemistry
1
4.
Which salts form coloured solutions when dissolved in water?
I.
II.
III.
FeCl3
NiCl2
ZnCl2
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
5.
When concentrated hydrochloric acid is added to a solution containing hydrated copper(II) ions,
the colour of the solution changes from light blue to green. The equation for the reaction is:
[Cu(H2O)6]2+(aq) + 4Cl–(aq) → [CuCl4]2–(aq) + 6H2O(l)
(i)
Explain what the square brackets around the copper containing species represent.
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(1)
(ii)
Explain why the [Cu(H2O)6]2+ ion is coloured and why the [CuCl4]2– ion has a different
colour.
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(2)
(Total 3 marks)
6.
Explain the origin of colour in transition metal complexes and use your explanation to suggest
IB Questionbank Chemistry
2
why copper(II) sulfate, CuSO4(aq), is blue, but zinc sulfate, ZnSO4(aq), is colourless.
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(Total 4 marks)
7.
(i)
State the full electronic configurations of copper, Cu, and the copper(I) ion, Cu+.
(2)
(ii)
Explain why copper(II) compounds in aqueous solution are coloured whereas
scandium(III) compounds in aqueous solution are colourless.
(2)
(Total 4 marks)
IB Questionbank Chemistry
3